Atlantoaxial Malformation
Many dwarf dogs have been found to have spinal problems, notably with Atlantoaxial malformation the joint between the C1 and C2 cervical vertebrae. Initially a number of dwarfs were found to suffer from unexplained neurological problems and also there were some instances of sudden death for no apparent reason. After much research by Annemarie Voorbij at the University of Utrecht, it was found that there is a link to the LHX3 gene which causes pituitary dwarfism, an issue most Vets and owners are unaware of. (see research paper link on this site). It must be stated that not all dwarfs suffer this condition so the association is a complex issue requiring further research. The first cervical bone (C1) is called the 'Atlas' and the second is known as the 'Axial' bone (C2), this first joint is different from all the others in the spine as there is no disc between them, the joint is stabilised by ligaments allowing a dog to move its head from side to side. Note: picture below shows normal Atlas /Axial bone formation (small gap)
Many dwarf dogs have been found to have spinal problems, notably with Atlantoaxial malformation the joint between the C1 and C2 cervical vertebrae. Initially a number of dwarfs were found to suffer from unexplained neurological problems and also there were some instances of sudden death for no apparent reason. After much research by Annemarie Voorbij at the University of Utrecht, it was found that there is a link to the LHX3 gene which causes pituitary dwarfism, an issue most Vets and owners are unaware of. (see research paper link on this site). It must be stated that not all dwarfs suffer this condition so the association is a complex issue requiring further research. The first cervical bone (C1) is called the 'Atlas' and the second is known as the 'Axial' bone (C2), this first joint is different from all the others in the spine as there is no disc between them, the joint is stabilised by ligaments allowing a dog to move its head from side to side. Note: picture below shows normal Atlas /Axial bone formation (small gap)
Incomplete Ossification
Dwarfs can be affected by incomplete bone formation ( incomplete ossification - growth hormone related) between C1 and C2, this can leave a large gap as shown below between the Atlas and the Axis allowing more movement than it should have, this produces an unstable joint.
Dwarfs can be affected by incomplete bone formation ( incomplete ossification - growth hormone related) between C1 and C2, this can leave a large gap as shown below between the Atlas and the Axis allowing more movement than it should have, this produces an unstable joint.
The MRI scan of a dwarf below shows the spinal cord being pinched, this is called subluxation and is due to the mis-alignment of C1 and C2 from excessive movement in the joint.
Symptoms
Research shows that in dwarfs there is a link for this condition to the LHX3 gene that causes pituitary dwarfism, therefore all dwarf dogs must be monitored for any neurological symptoms such as pain and discomfort around the neck area. Symptoms include: uncoordinated movement firstly in the hind legs and progressing to the front, holding their heads much lower than normal, head bobbing, knuckling where they occasionally drag their paws on the ground as they drag them, but it shouldn't be confused with DM. If you see any of these signs always get your dog checked by your Vet. Many of these signs can be seen quite early even when they are puppies and often lowering their heads to eat can be quite difficult or painful but noticing it in mild cases is really not very easy, a sudden yelp or cry of pain for no apparent reason other than a slight movement, or pain when getting up from a bed can all be signs of mild cases. Diagnosis is usually made by CT or MRI scan.
Research shows that in dwarfs there is a link for this condition to the LHX3 gene that causes pituitary dwarfism, therefore all dwarf dogs must be monitored for any neurological symptoms such as pain and discomfort around the neck area. Symptoms include: uncoordinated movement firstly in the hind legs and progressing to the front, holding their heads much lower than normal, head bobbing, knuckling where they occasionally drag their paws on the ground as they drag them, but it shouldn't be confused with DM. If you see any of these signs always get your dog checked by your Vet. Many of these signs can be seen quite early even when they are puppies and often lowering their heads to eat can be quite difficult or painful but noticing it in mild cases is really not very easy, a sudden yelp or cry of pain for no apparent reason other than a slight movement, or pain when getting up from a bed can all be signs of mild cases. Diagnosis is usually made by CT or MRI scan.
Treatment
Depending on how severe the problem is, surgery is technically possible and involves fusing the two cervical bones together in the normal position with screws and bone cement. This procedure relieves pain allowing the spinal cord to recover and generally the outcome is very good for some larger breeds where it does occur occasionally, but is not recommended for dwarfs. The operation has been performed on dwarfs but without success, this is a very specialist veterinary procedure and the costs can be extremely high.
Depending on how severe the problem is, surgery is technically possible and involves fusing the two cervical bones together in the normal position with screws and bone cement. This procedure relieves pain allowing the spinal cord to recover and generally the outcome is very good for some larger breeds where it does occur occasionally, but is not recommended for dwarfs. The operation has been performed on dwarfs but without success, this is a very specialist veterinary procedure and the costs can be extremely high.
For full details see research page
NOTE: It is recommended that harnesses are used for dwarfs and that collars are avoided, to prevent injury to the neck.
NOTE: It is recommended that harnesses are used for dwarfs and that collars are avoided, to prevent injury to the neck.
